Sydney FC and Central Coast Mariners provided quite a treat for local fans in the Round 17 clash at the Sky Blues so-called fortress on Saturday night.

Much has been made of Sydney’s immaculate form and impregnability, on its own turf at least, but cracks are beginning to show in the armour of a side still well clear at the top of the Hyundai A. League table, though shedding points from drawn games of late to give pursuing clubs like Newcastle Jets and the two Melbourne clubs a glimmer of hope.

Although the Mariners had beaten the Sky Blues earlier in the campaign, that 2-0 win was no evidence of their own sound credentials as they struggled to win other matches and goal-scoring was also proving difficult.

The result owed as much to derby rivalry and a mind-set that was switched on for the big day itself and here again much of the same psychological background was evident.

Sydney coach, Graham Arnold, later dismissed talk of the Mariners holding the key to unlocking his team’s dominance and suggested it was little more than coincidence that the Central Coast team was able to leave Sydney with a more than deserved 1-1 result, giving lie to some of their own recent poor form.

Arnold preferred to praise his players’ commitment in the face if a virus that had laid low many of his key men, while acknowledging the Mariners high work rate and application.

In the last few weeks Sydney’s Brazilian striker Bobo has been scoring a goal in virtually every game he plays, while attacking partner Milos Ninkovic has been a more than capable foil for the scoring machine, finding form in a team rich in skilled and adaptable players such as Polish import Adrian Mierzejewski, veteran skipper Alex Brosque and the two wingbacks Luke Wilkshire and MIchael Zullo.

Thanks to careful planning, the club has said, Sydney FC did not lose any players during the international break, remarkable considering their pre-eminence in Australian football as defending A. League champions.

By contrast Central Coast have had players away for a few weeks with the Australian Under-23 side in China at the prestigious AFC competition, including dynamic playmaker Daniel De Silva, young striker Trent Buhagia and youth team keeper Thomas Glover.

On this occasion they had also just lost their leading foreign attacking player, to homesickness and coach Paul Okon had far fewer selection possibilities than his Sydney counterpart.

The club had recently welcomed back Storm Roux from injury and swooped to sign unsettled Brisbane Roar attacker Petros Skapetis during the days leading into this match, but none of them, including the returning De Silva, were considered ready to start in such an important fixture.

The game began at a frantic pace, with Sydney offering the first positive signs that this might not be a tense, dour affair as Zullo made a strong early run in the opening 60 seconds to lay on a cross for Mierzejewski whose nod back from the far post intended for Bobo was to prove unproductive.

Central Coast especially through the lively Kwabena Appiah-Kubi began to offer something similar at the other end, keeping the highly-praised Sydney backline extra busy with his incisive running and abundant energy.

He almost opened the scoring in the third minute, after a penetrative run, just firing over at the end of his passage into the six yard area.

He was alert four minutes later when Sydney’s top tracking midfielder Josh Brilliante under-hit a pass back to his keeper which Kwabena quickly intercepted.

Up stepped former Sydney FC striker Blake Powell, whose career has seen him scoring prolifically for NPL1 side Apia Leichhardt before moving across the Tasman to Wellington Phoenix before settling at the Mariners, for whom he’s been mostly a fringe player until recently.

Powell’s prowess was easy to see as he stroked the ball effortlessly past Redmayne to send the Mariners’ small contingent of fans wild.

Both Kwabena and Andrew Hoole also went close during a fine opening spell for the visitors.

Ninkovic had the Sydney fans on their feet in the 15th minute, but Mariners’ keeper Ben Kennedy got down well to deny the Serbian striker.

Bobo, similarly, was looking to pull one back for his side, but he could only turn sharply and fire just wide in the 23rd.

Ninkovic and Mierzejewski also tested Kennedy, who was in good touch, as the first half continued to be played at a good pace and with both sides evenly matched.

Central Coast’s players were clearly lifting their game for this one, the derby factor playing a bigger part than some were ready to admit.

Kwabena continued to show a good turn of foot in the second half and was in the thick of the action, but his efforts may have left him drained and Okon wisely turned to his bench pulling off young prospect Lachlan Wales and Kwabena in turn.

Wales had very nearly made it 2-0 in first-half stoppage-time when finding himself in the goalmouth at point-blank range with the ball at his feet, but had insufficient time to react as he spooned the ball over the bar, much to his anguish and to the relief of the Sydney defence.

Those two who came off were replaced by the returning De Silva and new signing Skapetis and the changes only served to strengthen the Mariners’ chances as both players impressed during their time on the field.

But when they arrived on the scene Sydney had already drawn level, so fresh legs may have come too late to put the game to bed.

The equaliser came via the head of Bobo, off an Adrian Mierzejweski cross, from the right for once and expertly sent high into the net by the Brazilian.

That was the only goal the home side could manage and they’ve now drawn three of their last four games, this was their second in succession at home following their 2-2 draw against nearest rivals Newcastle Jets. They’d also been held to 0-0 by Adelaide United in between on their opponents’ ground.

Sydney still hold a handy lead, but owe as much to Newcastle dropping points as to their own unbeaten streak.

They will meet another motivated opponent on Australia Day in Melbourne Victory while Central Coast Mariners have an opportunity to cash in on Brisbane Roar’s terrible form of late when the sides meet on Saturday night at Central Coast Stadium.

There’s every chance that players like Skapetis and De Silva will start, while the more settled Sydney side appears now to have fewer options available off the bench, so established have been most of their regular players that chances for fringe players have been few and far between.

This result and the overall shape of the game may come as a wake-up call for the Sky Blues.

Central Coast have some depth, but goal-scoring has been an issue and confidence as a result has not always been there. Saturday night with renewed confidence drawn from their impressive showing in Sydney could help lift them toward the play-off positions which is obviously the ultimate aim.